I've seen the word "hushers" used to describe the Russian consonants ч, ш, щ, ж (especially in the context of spelling rules). Is this an accepted linguistic concept or is it just a convenient name coined to help language learners?
I understand that they make a "hushing" sound, but what actually distinguishes these consonants linguistically (phonetically/phonologically)? It seems that the letters ш/ж are retroflex consonants and ч/щ are alveolo-palatal. Are these the only distinguishing feature that makes them "hushers"?
If I want to be more precise linguistically, could I just refer to them as "retroflex and alveolo-palatal consonants"? Or is there some other feature I am missing?